1. Field of the Invention
The present invention relates to a tailgate lift assembly and particularly to a device which allows a tailgate which is hingedly attached to a trailer to be raised and lowered with relative ease due to the biasing of the lift assembly.
2. Description of the Prior Art
Prior art tailgate lift assemblies which are being utilized in combination with a trailer and tailgate typically use hydraulics or other cantilevered pivot arms in order to aid in the raising and lowering of the tailgate. These prior art tailgate lift assembly devices further traditionally require integration into the side wall or bed of the trailer in order to adequately provide biasing of the tailgate in the upward or downward direction. Such biasing allows the tailgate to be raised and lowered with relative ease.
However, the integration of the biasing devices into the side-rail or bed of the trailer proves to be difficult in the manufacturing of the trailer device or in modifying of the trailer device due to the structure of the pivoting arms or the inclusion of the hydraulic support cylinders.
Further devices have provided a mechanism for lifting tailgates wherein cables may be utilized, but which must necessarily be positioned such that interference in the truck bed is required. U.S. Pat. No. 4,601,485 discloses such a mechanism wherein a cable interferes with a trailer hitching device for a fifth wheel vehicle in order to actuate raising and lowering of the tailgate.
Other mechanisms are known which combine spring type devices and hydraulic means for raising and lowering gates from a vertical and horizontal position. U.S. Pat. No. 3,303,613 discloses utilization of multiple spring devices in addition to hydraulic cylinders in order to provide biasing means for raising and lowering of the gate. However, utilization of the above-listed devices proves to be unusable in combination with a trailer due to proper positioning of the material elements and the inability of integrating these elements with a standard trailer bed and side rail.
These and other devices of the prior art fail to be easily integrated with presently existing trailers and require extensive engineering and manufacturing at the time of assembly of the trailer.
In the prior art, there does not exist a simplified unit for providing a tailgate lift assembly which works in combination with the trailer and the tailgate such that the lift assembly is integrated with the trailer side-rail, which provides adequate biasing of the tailgate for relative ease of raising and lowering the tailgate and which may be readily integrated with existing trailer side-rails.
The present invention resolves the above disclosed drawbacks of the prior art devices. The tailgate lift assembly of the present invention provides a means to bias a tailgate from the trailer utilizing a lift assembly wherein the assembly is provided along the side-wall or rail of the trailer. The lift assembly is connected to the tailgate through use of a cable which is properly biased through utilization of a spring and multiple rollers. The design of the present invention allows for a lift assembly to be readily integrated with existing trailers and also provides a relatively inexpensive design which may be utilized in the original manufacturing of the trailer such that relatively easy manufacturing may be found.
The tailgate lift assembly of the present invention combines utilization of a biasing spring in a housing member, the housing member being placed on the upper portion of the trailer side rail. The housing contains therein the biasing spring which is anchored within the housing and connected to the tailgate by a cable. The cable may be intertwined around a first and a second roller so that upon raising and lowering of the tailgate the cable may move axially within the housing with relative ease. Further, provided at the attachment point of the cable to the tailgate, adjustment means may be provided such that the length and thereby the tension of the cable may be readily adjusted.
It is therefor an object of the present invention to provide a tailgate lifting assembly which may be readily integrated with the side-rail of an existing trailer.
It is a further object of the present invention to provide a tailgate lift assembly which allows for relatively easy manufacturing and integration with both the trailer and the tailgate such that overly burdensome hydraulic mechanisms or pivoting arms are not required.
An additional object of the present invention is to provide a tailgate lift assembly wherein a biasing spring is operably connected to the tailgate through use of a cable and wherein the cable is subjected to a guiding mechanism such that it may readily slide axially within the interior of the housing.
An additional object of the present invention is to provide a mechanism for adjusting the length of the cable such that the amount of biasing and tension within the tailgate lift assembly may be changed.
A further object of the present invention is to provide a tailgate lift assembly which can be readily integrated with existing trailers by application onto the side-rail of the trailer thereby connecting the tailgate to the side-rail with a biased cable. Thus, trailers which do not have any lifting assemblies located thereon may be readily retrofitted with the tailgate lift assembly of the present invention.